This invention relates generally to cable television systems and taps used in such systems, and more specifically to the provision of AC power to subscriber premises in a cable television system.
Cable television systems typically transmit information signals to subscriber equipment, such as televisions, telephones, set top units, and computers. The cable television system generally includes headend equipment for transmitting and information signal and taps that tap the signal off to system subscribers. Such a cable television tap includes an input port for receiving the signal, and output port for passing the signal through to other portions of the distribution system, and subscriber ports, each of which couples a portion of the signal to a subscriber. A tap commonly includes four, eight, or sixteen subscriber ports, although an even larger number of subscriber ports can be included if necessary.
AC (Alternating current) power can also be provided through the cable television system for powering telephones and other subscriber equipment. In this case, the AC power typically travels through the same distribution system, including the taps, so that it can be provided to the subscriber on the same communication medium that provides the information signal. However, regulations in some geographic regions prohibit the provision of information signals and AC power to subscriber equipment on a single coaxial cable that is run from the main cable television line to the house or other subscriber premises. Therefore, in at least one conventional configuration, a system operator has been required to provide devices for splitting the AC power from the information signal so that the AC power can be transmitted to the subscriber premises using twisted pair cables while the information signal is transmitted from the tap to the subscriber premises using conventional coaxial cables. A disadvantage to the use of this type of device, however, is that a separate filter device must be connected to the output of each subscriber port of each tap. As a result, modification of the cable television system hardware in this manner can become very expensive and very labor intensive.
Thus, what is needed is a better way to separately provide AC power and information signals to subscribers in a cable television system.